The ignition of primer mixtures associated with ordnance such as ammunition cartridges by electrical means, is generally well known in the art as disclosed for example in U.S. Pat. Nos. 3,090,310, 3,413,888, 4,332,098 and 4,386,567 to Peet et al., Kaley, Estenevy and Ciccone et al., respectively. The Peet et al. and Ciccone et al. patents furthermore disclose the protective enclosure of a primer retention cup by an insulating liner within a cartridge case. The Estenevy patent, on the other hand, features battery operated electrical circuitry through which a trigger current is supplied to the primer from a power relay thyristor upon closing of a trigger switch connected to a voltage storing capacitor charged by the battery through a dc pulsating voltage converter.
While the relevant teachings of the foregoing referred to prior art patents are allegedly designed to improve firing accuracy, such teachings do not deal with the problems arising during the interval between release of the movable firing pin or hammer in response to a firing command and the instant that such firing pin strikes or contacts the primer. During such intervals, referred to as lock time, vibrations are generated by movement of the firing pin to introduce firing inaccuracies. Thus, firing accuracy for rifles may be improved by increasing firing pin speed to reduce lock time. Increase in speed of the firing pin is however limited by the degree to which its weight may be reduced and/or the extent to which the strength of the drive spring for the firing pin may be increased.
It is therefore an important object of the present invention to improve firing accuracy of ordnance with an electrically activated primer having a mechanically displaced firing pin, by substantially reducing the lock time interval beyond the capacity available through reduction in weight of the firing pin and/or increase in its drive spring strength.